The present invention relates to vehicular lamps. More particularly, the invention is directed to a vehicular lamp having a reflecting surface divided into three regions in such a manner that unwanted horizontal diffusion in the resulting light distribution pattern due to secondary reflections at the left and right side walls of a lamp body does not occur.
In order to streamline the shape of a vehicular body in accordance with aerodynamic and styling considerations, the front nose a of the vehicle is, as indicated by a two-dot chain line in FIG. 12, curved from the middle to the side edge portions thereof. This design imposes certain requirements on the shape of the headlamp.
A vehicular headlamp may include both a cornering lamp and a turn signal lamp. For such lamps, the shape of the reflector is designed to allow the front lens disposed in front of the reflector to be stepless or nearly stepless. That is, the light distribution pattern of the lamp, which must conform to applicable governmental standards, is obtained only through the light distribution control of the reflector.
FIG. 12 schematically shows the construction of a turn signal lamp b. The turn signal lamp b is located adjacent a headlamp c indicated by a one-dot chain line. Reference character d denotes a lamp body. A predetermined region on the inner surface of the lamp body is provided with a reflective coating so that a reflecting surface c is formed. The front-to-rear length of a side wall f that is adjacent to the headlamp c is longer than that of a side wall g that is remote from the headlamp c. The front lens h that covers the front of the lamp body d is curved so that the surface thereof conforms to the shape of the front nose a of the vehicle. Reference character i denotes a lamp bulb, which is located at a predetermined position inside the lamp body d.
In the turn signal lamp b, the distance between the portion close to the side wall f in the reflecting surface e and the portion of the front lens corresponding thereto is relatively long. As a result, part of the light emitted from the lamp bulb i and reflected at the reflecting surface e is subjected to secondary reflection by the side wall f, as indicated by rays of light j in FIG. 12. That is, the presence of the side wall f causes unwanted horizontal diffusion in the light distribution pattern. As a result, it is difficult to obtain sufficiently horizontally diffused rays of light with the reflecting surface e.